If it's true that you can't talk about global development without discussing gender equality, it's also true that you can’t dive deep into gender in poor countries without talking about menstruation. However, the international conversation on this topic tends to be in hushed tones. Sometimes, even the most pragmatic global health and development experts get uncomfortable when the subject comes up.

On the other hand, we've been impressed by some funders, like Michele Sullivan of the Caterpillar Foundation, who don't shy away from talking about how the challenges around menstruation can hold women back. Sullivan mentioned this issue in an interview with IP last year in regard to WASH issues, noting that menstruation can be especially difficult for girls to manage without easy access to bathrooms, and this can stop young girls from engaging in school and society just when they need to step up.

The Gates Foundation and other major development funders like Ford have also occasionally addressed this issue with grants or given attention to it. Just a few months ago, the director of policy and advocacy at WaterAid, Lisa Schechtman, wrote about menstruation on the Gates Foundation's blog, pointing out that on any given day, "more than 800 million women and girls between the ages of 15 and 49 are menstruating worldwide," and for many, this regular event creates serious problems. Yet, said Schechtman, discussion of menstruation hygiene management "rarely appears in donor strategies, national government policies or advocacy agendas."

Schechtman argued: "It’s time to bring difficult issues like menstruation out of the shadows... Menstrual hygiene is a harbinger of gender equality."

In wealthy countries, monthly periods are more of a tiresome nuisance and any period-related health issues are generally cleared up by a doctor’s visit. In poor countries, it’s an entirely different story.

A 2012 study by WaterAid indicated that 48 percent of girls in Iran and 10 percent of girls in India believed that menstruation was a disease.

A UN Children’s Fund study indicated that one in 10 African girls skip school because they have their periods.

Approximately 70 percent of all reproductive diseases in India are a result of poor menstrual hygiene.

Monthly menstruation is also cited as the No. 1 reason why girls in developing countries miss a significant number of school days per year, or drop out altogether.

Those statistics just scratch the surface. Schechtman writes that the taboo and misinformation around menstruation can have a "powerful ripple effect, leading women and girls to be subjected to stigma, discrimination, violence, or even have food, water, shelter and other shared goods be withheld from them."

Improved sanitation systems are a key solution here, and this issue now gets good play in the WASH community. But there's another, more simple solution to menstruation challenges—better access to sanitary pads.

Many girls and women in poor countries do not have access to basic menstrual products like tampons and pads. Sometimes, this is because they're unavailable, but more commonly it’s because they are too expensive. (This can be a problem in the U.S., too, I should mention.) Thankfully, there are are a number of nonprofits and businesses working to address this problem. Among them is ZanaAfrica, which sees opportunity in the niche of menstrual hygiene management.

The group is a Nairobi-based social enterprise that produces affordable sanitary pads. It was founded by Megan White Mukuria, a Harvard graduate. After securing a hefty $1 million investment from Grand Challenges Canada, it raised matching funds privately from TripAdvisor and the Stewardship Foundation. The investment allowed the company to transition from pilot to proof-of-concept, leading to a Phase II Grand Challenges Exploration grant, which is cofunded by Grand Challenges Canada and the Gates Foundation.

ZanaAfrica will use the investment to scale up production of its sanitary pads as well as provide free menstrual hygiene management education in Africa, beginning in Kenya. The company has also developed a tiered distribution model that leverages partnerships with social enterprises, health workers, stores and roadside kiosks to ensure that women and girls have easy access to its products.

The Gates Foundation’s Grand Challenges Explorations focuses on innovations in global health research. Challenge winners receive initial funding of $100,000 over 18 months. Should the project show a good deal of promise, Gates ups the ante to $1 million or more.